Many passenger and other vehicles are now equipped with supplemental restraint systems (SRS), such as front or side airbags, to protect vehicle occupants in the event of an accident. However, while such SRS can in many cases prevent or mitigate the harm which would otherwise occur to a vehicle occupant in an accident situation, in some circumstances it is contemplated that they can exacerbate the injury to a vehicle occupant. Specifically, SRS such as airbags must deploy rapidly, in the event of an accident, and this rapid deployment generates a significant amount of force that can be transferred to the occupant. In particular, children and smaller adults can be injured by the deployment of airbags as they both weigh less than full sized adults and/or they may contact a deploying airbag with different parts of their bodies than would a larger adult.
For these reasons, regulatory agencies have specified the operation and deployment of SRS. More recently, regulatory bodies, such as the National Highway Transportation and Safety Administration (NHTSA) in the United States, have mandated that vehicles be equipped with a device that can automatically inhibit deployment of the passenger airbag in certain circumstances, such as the presence of a child in the passenger seat or the seat being empty.
To date, such devices have been implemented in a variety of manners, the most common being a gel-filled pouch in the seat base with an attached pressure sensor which determines the weight of a person in the passenger seat and, based upon that measured weight, either inhibits or permits the deployment of the airbag. However, such systems are subject to several problems including the inability to distinguish between an object placed on the seat and people on the seat, the presence of child booster/restraint seats, etc.
It has been proposed that image-based sensor systems could solve many of the problems of identifying and/or classifying occupants of a vehicle to control SRS but, to date, no such system has been developed which can reliably make such determinations in real world circumstances wherein lighting conditions, the range of object variability, materials and surface coverings and environmental factors can seriously impede the ability of the previously proposed image-based systems from making a reliable classification.
It has also previously been proposed that image-based systems and methods may be useful in classifying matters such as a measure of driver alertness, by acquiring and processing images of the driver within the interior of the vehicle, or classifying the presence of passengers within the vehicle allowing for the optimized control of vehicle environmental systems (such as air conditioning) and/or entertainment systems by classifying the occupancy of one or more vehicle seats. However, to date, it has proven difficult to achieve a desired level of reliability for such systems.
It is desired to have an image-based system and method that can determine a classification relating to the interior of the vehicle, such as the occupancy status of a vehicle seat, from one or more images of the vehicle interior.